Literature Data and Corrosion Testing of Hard Anodized and Duplex Sealed 7075-T7351 and 7050-T7451 Wrought Aluminum Alloy Plates after Cyclic Loading

Heat treated 7000-series aluminum alloys exhibit the highest strength and toughness amongst wrought aluminum alloys, and are used for a variety of applications in the defense and the aerospace industry. The corrosion resistance of these alloys is strongly dependent on final thermo-mechanical and tempering treatment. Many surface modification techniques are used to protect these alloys against general, exfoliation and pitting corrosion. Hard anodizing is a surface modification technique that imparts corrosion and wear resistance to 7000-series aluminum alloy parts. However, if the anodized parts experience cyclic loading conditions, there is a risk that the brittle anodized layer may undergo cracking thereby compromising the corrosion resistance of the 7000-series aluminum components in service. This paper details the results of an investigation undertaken to evaluate the corrosion behavior 7075-T7351 and 7050-T7451 aluminum samples that were anodized and duplex sealed prior to cyclic loading. The aluminum samples were hard coat anodized per MIL-A-8625F and cycled between 0-31 ksi (0-214 MPa) for 4000 cycles prior to the accelerated corrosion tests. A hypothesis to explain the corrosion behavior is presented.

File Size: 404K

See papers presented at AeroTech Congress & Exhibition, September 2007, Los Angeles, CA, USA, Session: Advanced Metal Materials, Fabrication and Joining Processes

Purchase more technical papers and save! With TechSelect, you decide what SAE Technical Papers you need, when you need them, and how much you want to pay. Learn more >